This project will develop two small, user-friendly, personal, ambulatory monitors of eye blink activity for recording: 1) time between eye blinks with feedback relevant to drowsiness indicated by decreased blinks; and 2) number of eye blinks per minute for ambulatory sleep-wake recording and research with blinks. Drowsiness and impaired alertness is a major heath problem. Shift work, demanding life schedules, social use of alcohol and disease produce wake-time sleepiness which becomes a health and safety problem when operating equipment or driving a motor vehicle. Monitor 1 provides an ambulatory monitor supporting sleep deprivation research and also a personal aide to alert individuals to correct problems of sleepiness. Ambulatory monitoring for sleep disorders is needed to reduce costs and improve screening, diagnosis and treatment evaluation. The blink rate monitor provides a better indicator of sleep than other indirect measurements such as physical activity. Spontaneous blink rate is also of research interest and is used as a clinical indication of alterations in dopaminergic activity. The monitors will use technology developed by IMS for activity monitoring and experience gained by IMS in use of small peizo sensors. Monitors will be evaluated for normals and sleep disorder patients using field studies and sleep deprivation.